Vat dyestuffs of the anthraquinone series



Patented May 19, 1936 PATENT OFFICE VAT DYESTUF'FS OF THE ANTHRAQUINONESERIES Hans Krzikalla and Walter Limbacher, Ludwigshafen-on-the-Rihine,

Germany, assignors to General Aniline Works, Inc., New York, N. Y., acorporation of Delaware No Drawing. Application June 2'7, 1935, SerialNo. 28,768. In Germany July 6, 1934 3 Claims.

The present invention relates to vat dyestuffs of the anthraquinoneseries.

We have found that valuable vat dyestuffs of the anthraquinone seriesare obtained by condensing alpha-aminoanthraquinone with2-hydroxy-3-methylbenzene-l-carboxylic acid or 3-methyI-G-hydroxybenzene-l-carboxylic acid. In order to prepare thedyestuffs, alpha-aminoanthraquinone may either be treated with thechloride of the methylhydroxybenzene carboxylic acid, preferably in thepresence of a diluent, or a mixture of alpha-aminoanthraquinone and themethylhydroxybenzene carboxylic acid may be treated in a suitablediluent with an agent. for withdrawing water, as for example thionylchloride or phosphorus oxychloride. Suitable diluents are for examplenitrobenzene or ortho-dichlorbenzene.

The dyestuffs are very readily vatted and dye wool clear, uniform yellowshades which are distinguished by excellent fastness to light, steamingand washing.

The following example will further illustrate how the said invention maybe carried out in practice but the invention is not restricted to thisexample. The parts are by weight.

Example 223 parts of alpha-aminoanthraquinone and 170 parts of2-hydroxy-3-mlethylbenzene-l-carboxylic acid are introduced into 4000parts of commercial ortho-dichlorbenzene. 140 parts of thionyl chlorideare then allowed to drop in dur- 35 ing the course of about two hours atfrom 60 to 70 C. The whole is then slowly heated to boiling and thenallowed to cool after about 2 hours, the dyestufi thusbeing crystallizedin the form of yellow needles. It is filtered off, washed and dried. 40It dissolves in concentrated sulfuric acid giving an orange coloration.When the solution is poured into water the dyestufi is precipitated inthe form of a pale yellow fiocculent deposit. It dyes wool from a mildalkaline vat very clear greenish yel- X CH3 i I I r t -Q in which one Xstands for the hydroxyl group the other X being hydrogen.

2. The vat dyestuff having the formula:

3. The vat dyestuff having the formula:

OH OH:

HANS KRZIKALLA. WALTER LIMBACHER.

